Syria's continued use of chemical weapons breaches the Geneva Protocol, David
Blair writes

Yes. After at least 1,400 people were gassed to death in the suburbs of Damascus on Aug 21 last year, Bashar al-Assad avoided a US military strike by agreeing to hand over his chemical weapons for destruction. Of a declared stockpile of 1,300 tonnes, 92.5 per cent has now been shipped out of the country (although that should have been 100 per cent by Feb 4, so the deal is well behind schedule). However, that agreement only covered sarin, mustard and VX nerve gas, together with the “precursor” chemicals used to make them. It did not include chlorine and ammonia, which have a wide array of civilian uses - but can also be deadly. The evidence suggests that Syria’s regime has carried on gassing its enemies using substances not covered by last year’s agreement.

Do these attacks break international humanitarian law?

The Geneva Protocol of 1925 bans the “use in war” of “asphyxiating, poisonous or other gases” along with “all analogous liquids, materials or devices”. If converted into lethal gas and used to kill people, chlorine and ammonia would fall within this broad definition. Chlorine gas was used as a chemical weapon during the First World War, so the Protocol’s authors would have had it in mind. It would be hard to defend the Assad regime from the charge of breaking this agreement, which Syria signed in 1968.

However, the Geneva agreement said nothing about producing or stockpiling poison gas. The Chemical Weapons Convention (CWC) of 1993 filled this gap by prohibiting the manufacture or possession of these weapons. Syria joined the CWC last November as part of the agreement to surrender its chemical arsenal.

Whether Syria’s armed forces have now broken the CWC depends on your definition of a chemical weapon. Syria might argue that chlorine and ammonia can never be weapons because of their civilian uses. If, however, these substances are loaded inside bombs in the form of gas and then dropped onto targets by military helicopters – as the evidence suggests – then it would be hard to deny this amounts to weaponisation. If so, Mr Assad will have become the first leader ever to break both the Geneva Protocol and the Chemical Weapons Convention.

How dangerous are chlorine and ammonia?

Both have harmless civilian applications – chlorine as a cleaning agent and ammonia as a fertiliser. However, both can be deadly if inhaled in sufficient quantities. They kill by reacting with water in the lungs to produce an acid that burns the respiratory system. Unlike sarin and VX, which are solely designed to kill, chlorine and ammonia are both dispersed by the atmosphere very quickly. This might explain the relatively low death toll from the recent attacks.

Where might the chlorine and ammonia have been obtained?

Both are relatively easy to manufacture. Like many countries, Syria will have the ability to produce them without help.

What happens next?

The Organisation for the Prohibition of Chemical Weapons (OPCW) announced on Tuesday that it would send a team to Syria to investigate the attacks. If this body confirms that gas is once again being used as a weapon, then the world’s leading powers will have to decide how to react. Russia and China would almost certainly prevent the Security Council from agreeing a response. One option would be for America to supply Syria’s rebels with surface-to-air missiles, allowing them to shoot down the helicopters used in these attacks. The US has always been unwilling to take this step, fearing that any such weapons would find their way into the hands of terrorists.